The one that is in there is probably about at its limit, though it might have another revolution or two.  The picture above is completely unwound.  If I unwind it any further than that, it will try  spring forward until it hits that point again.    The second one that I ordered is longer but it appears to me that the spring probably does not have as much force.  I haven't unpacked it yet to test it.  

--Nathan, TX. Hire the lazy man. He may not do as much work but that's because he will find a better way.